3 Best and Worst Oils For Your Health

Despite what doctors have said for decades--that fat clogs arteries, causes heart attacks, and, well, makes us fat--the "low-fat" mantra is quieting down. "Some fat is actually good for you," says Alice H. Lichtenstein, director of the cardiovascular nutrition laboratory at Tufts University.To get the most from fats, you need to go beyond olive oil. Open your cupboard to new flavors, cooking temperatures--and health benefits--by diversifying your oils. See our picks for the most and least healthy oils for cooking, after the jump.

MOST HEALTHYThe healthiest oils are rich in these healthy fats:

Polyunsaturated: It's time to make polyunsaturated fats, like those in grapeseed and walnut oils, staples. Many scientists consider them the healthiest of all because they contain omega-6 and omega-3 fatty acids, which lower "bad" LDL cholesterol, increase "good" HDL cholesterol, and may decrease risk for type 2 diabetes.

Monounsaturated: Round out the list with fats like avocado and olive oils, which may boost good cholesterol.

All fats have about 120 calories per tablespoon, so moderation matters (fats should make up 25 to 35 percent of total caloric intake). But oil's nothing to fear, so get cooking with these three favorites.

1. Grapeseed OilHigh in polyunsaturated fats and vitamin E, grapeseed oil has a high smoke point, which makes it a good substitute for olive or vegetable oils when stir-frying and sauteing. And because it's virtually flavorless, it lets top-notch ingredients stand out (like the balsamic vinegar you lugged back from Italy).2.Walnut OilThe ultimate finishing touch. This flavorful, nutty oil doesn't stand up to heat, but it's fantastic in salad dressings or as an accent to winter vegetables. It contains polyunsaturated fats, including alpha-linolenic acid--a heart-healthy, anti-inflammatory omega-3--and vitamin K, which may strengthen bones.

3. Avocado OilDrizzle it over lean cooked fish to lend fullness, or whisk with citrus juice for a bright vinaigrette. Like other specialty oils, this monounsaturated fat-rich oil is pricier than the everyday stuff, so refrigerate it to keep its subtle avocado flavor fresh. (Bring it to room temperature before using.) --Melinda Wenner Moyer

LEAST HEALTHYThese are top offenders for general health, heart health and weight management. When in doubt, look at the nutrition label; the lower the saturated fat content, the better. Most healthy oils have around 2 grams of saturated fat per 1 tablespoon serving, so leave anything with soaring saturated fat on the shelf. Here are the top three oils you should avoid:

1. Anything That's "Partially Hydrogenated"This can be anything, like partially hydrogenated vegetable and soybean oil. Hydrogenated oils and fats are extra-saturated and can increase "bad" LDL cholesterol and decrease "good" HDL cholesterol. They're typically found in processed foods and snack items with a longer shelf-life, so double-check those, too.

3. Cottonseed oilCottonseed oil has a high ratio of saturated fat and may also contain traces of pesticides used when farming cotton crops. Double-whammy!

Oil with a Bad RapRecent research shows some potential health benefit to coconut oil, particularly virgin coconut oil. Although it's mostly comprised of saturated fat, the type of saturated fat (MCT's--medium chain triglycerides rather than long chain) are metabolized differently and pose less risk on cholesterol and heart disease. --Marissa Lippert